In addition, I understand you can search B2M in CSF (CNS involvement) and in urine (kidney involvement).

Thus I was wondering whether PWME do have elevated B2M either in blood, CSF or urine. It seems interesting to me because I am CMV: IgG+ IgM- PCR-
Anyway I am been testing for this in order to discard blood CA, suspected by a gastro due to swollen lymph nodes. (Don't think so)

Thus, any experiences with elevated B2M in blood, CSF or urine not correlated with blood CA but with ME/CFS ??? (My layman guess is that results are slightly elevated not enough to become concerned about it according to a non-ME/CFS specialist view, as usual )